Table 1.

Definitions of the medical categories and examples.

Categories	Examples of tweets
Effectiveness (refers to the ability or inability of a contraceptive method to prevent an unplanned pregnancy)	• IUDs are more than 99% effective in preventing pregnancy, and some can work up to 12 years, but a 2016 survey found that many women still do not know anything about these longer-acting reversible contraceptives • Pediatricians call IUDs “first-line” birth control for teens • The IUD is 20 times more effective than birth control pills, as studies have found • <1% of women who use an IUD become pregnant in 1 year, compared with 9% of women who use birth control pills
Side effects (refer to any effect that is secondary to the one intended; we also included tweets discussing tolerability of the drug)	• This form of IUD may carry a higher risk for breast cancer in certain women • A large study of Danish women finds that birth control pills and IUDs that release hormones carry a risk for breast cancer • Women taking newer forms of birth control pills have higher risk of blood clots, as studies have shown • Teenage girls who use birth control pills are more likely to cry, sleep too much, and experience eating issues than their peers who do not use oral contraceptives, according to a recent study published in the medical journal JAMA Psychiatry. • “20–30% of women on birth control pills experience depression. This study was terminated after 3% depression in men” • A British woman is dead after developing a blood clot caused by birth control pills
Other	• #Doh, Not Again … “We forgot the birth control pills” -Levi Johnston on prego girlfriend • Do women on birth control pills prefer men with less masculine facial features?

IUD, intrauterine device.